Australia's High Court Rules Climate Impact Must Count in Coal Mine Approvals

Australia's High Court has dismissed an appeal by mining company Mach Energy, upholding earlier rulings that the planned expansion of the Mount Pleasant coal mine in New South Wales was approved unlawfully. The decision came on October 7.

Mach Energy had wanted to extend the open-cut Hunter Valley mine's life by more than 20 years, to 2048. The court found that the state's planning commission failed to consider imposing conditions that would limit emissions to the greatest extent practicable, and that the local impacts of the coal's heat-trapping emissions had not been properly assessed.

The people behind the case

The challenge was brought by two retired science teachers, Wendy Wales and Tony Lonergan, who campaigned through a local community group. Campaigners describe it as the first climate case to reach the High Court.

"Today, the highest court in the country agreed that those decisions have to account for the damage they cause." — Tony Lonergan

Lead counsel Anita O'Hart called it a "historic" piece of environmental law.

Why it matters

• Scope: Mach argued that coal shipped overseas and burned there could not be clearly linked to impacts felt locally. The court did not accept that approach in this case.
• Precedent: Environmental groups say the ruling sets a binding national precedent that climate harm must be weighed when fossil fuel projects are assessed.

Context

Lonergan stressed that the ruling does not end coal mining overall; it ends approvals that ignore climate impacts. Mach Energy said it was "disappointed with the outcome" but accepts the decision, and said it will keep pursuing options to secure the mine's long-term operation. Industry voices have also warned the ruling could create uncertainty for other projects, so how it plays out across future approvals remains to be seen.